Oscillating piston for fluid meters



Oct. 8, 1935. R T JR 2,016,347

OSCILLATING PISTON FOR FLUID METERS Filed March 6, 1934 I. J I 6 i m t tI wi M Patented Oct. 8, 1935 UNITED STATES PATENT OFFIQE.

OSCILLATING PISTON FOR FLUID METERS Richard H. Smith, Jr., Hamilton,Mass. Application March 6, 1934, Serial No. 714,294

2 Claims. (01. 78-37) My invention relates to improvements in fluid ringwith its web is slotted at l to fork over or emmeters, and is hereinillustrated as embodied in a brace the bridge or division plate 2. Theportion meter of the oscillating piston type which is parof the post 8extending below the web guides the ticularly adapted for use indispensing and meas-' piston within the measuring chamber around a uringfluids such as water or oil. Meters of the roller I4 mounted in a well 9and the portion ex- 5 type referred to commonly comprise a measuringtending above the web engages a driving arm, by chamber having therein apiston or similar part which its motions are transmitted through a setof arranged for oscillation under fluid pressure. intermediate gears tothe register which indicates Such meters, as heretofore constructed,frequentthe quantity of fluid displaced. The indicating 1o 1y becomeinaccurate or inoperative because of mechanism and connections are notshown herein, 10

the clogging of the moving parts by hard particles but may be of anysuitable known type.

of foreign matter which pass the filter screen or- The piston itselfdoes not rotate about its own dinarily used in the fluid supply line orwhich are axis, but slides or oscillates back and forth, with formed inthe meter itself by erosion. These parthe walls of the slot 1 engagingopposite sides of ticles may become wedged between the piston and thebridge, and always moving in the direction the walls of the measuringchamber with the reof the flow of the fluid through the meter. The

sult that the normal operation of the piston is arrangement of the portsis such that they are prevented. continually open to enlarging andcontracting In view of the foregoing, it is an object of my spaces sothe fluid has free flow at all times.

invention to devise an improved meter of the type The displacing actionof the piston continues as 20 mentioned which will not become clogged orinlong as fluid is passed through the meter and since operative throughthe accumulation of dirt or the incoming fluid continually tends toforce itself other foreign matter. To this end, and as illusbetween thewalls of the piston and the measurtrated, the invention provides a meterhaving a ing chamber the piston is caused to oscillate about measuringchamber and a piston arranged to osthe bridge 2 as a pivot but the post8 is driven in 25 cillate within the chamber under the pressure of acircular course under the guidance of the wall fluid supplied to thechamber, the piston being of the well 9 and the roller 14. soconstructed that particles of foreign matter The piston must at alltimes be free from side. cannot become wedged between the walls of thestrain and a small clearance is allowed between chamber and the pistonin such manner as to prethe piston outer wall and the cylindrical innerwall 30 vent normal operation of the piston. Preferably, of the chamberwhen the piston occupies the posiand as shown, the periphery of thepiston is protion shown in Fig. 2 or when the inlet port is vided withone or more grooves extending in the open and the outlet port of thechamber is closed general direction of the flow of the fluid through bythe piston.

the meter and adapted to receive the particles of The piston is providedwith a recess or groove in 35 foreign matter and conduct them to theoutlet of which extends along the lower outer edge portions the meter.of its periphery. This groove is important in that The invention in itsvarious aspects is disclosed it provides clearance between the innerportion of in t e following de a s ription and in the the lower sidewall and bottom of the measuring accompanying drawing, and will bepointed out in chamber and the outer wall of the piston 5. Thus 40 theclaims. when hard particles of foreign matter of sufficient In thedrawing, size to clog the piston enter the chamber they will, Fig. l isa sectional side view of the measuring because of their weight, drop tothe bottom of the cham r and associated parts f a m r m ychamber andupon oscillation of the piston will ing my invention; and be pushedtoward the wall of the chamber by the 45 Fig. 2 is a plan view of themeasuring chamber piston but will be positioned, out of the way, in andparts with the division plate broken away. the groove II] when thevariable line of contact of The type of meters of which this inventionis to the piston with the wall of the chamber passes the be applied to,consists generally of a cylindrical particle. casting comprising ameasuring chamber I with It is to be noted that, since the groove l0 ex-50 a bridge or division plate 2 having an outlet port tends in thegeneral direction of the flow of fluid 3 on one side and an inlet port 4on the other side. through the meter, and since the small opening Thepiston 5 is a cylindrical ring having a cenformed by the groove betweenthe piston and the tral horizontal perforated web 6 which carries a wallof the chamber rapidly shifts its position in post 8 at the centralportion thereof. The piston the direction of the flow, there will belittle or no 55 leakage of fluid past the piston because of the groove.

In practice, it has been found that after a few oscillations of thepiston grit or other foreign material entering the chamber is dischargedat the outlet. If desired, additional grooves H higher up on theperiphery of the piston may be included to collect and dispose ofparticles so light that they do not drop to the bottom of the chamber.Thus, it will be apparent that I have provided a comparatively simpledevice which eliminates any possibility of grit or the like to becomewedged between the piston and the chamber and create friction thuscausing the meter to function improperly or stop it entirely,

Having described my invention, What I claim as new and desire to secureby Letters Patent of the United States is:--

l. A fluid meter comprising a measuring cham- 20 her, an inlet port, anoutlet port, and a piston arranged to oscillate in the chamber incontinuous engagement with the wall of the chamber, said piston having aperipheral groove extending around the circumference of the piston forthe passage of foreign matter between the piston and the wall of thechamber in the direction of flow of fluid.

2. A fluid meter comprising a measuring chamber having a vertical wall,an inlet port, an outlet port, and a piston mounted in the chamber formovement about a vertical axis with successive portions of its outersurface in engagement with the wall of the chamber, the outer surface ofsaid piston adjacent to the bottom of the chamber being recessed aroundthe circumference of the piston to provide a passage between the sidewall of the piston and the wall of the chamber for conducting foreignmaterial toward the outlet port.

